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1.
Summary An outline is given of a method of estimating the number of hours during which the combine harvester can be operated in a certain harvesting period. This method is based on a study of the relation between the daily rainfall and the hourly estimates by 60 observers of the possibility of combine harvesting (weather-working hours).Over the years 1964, 1965 and 1966, the relationship between the possibility to combine harvest and the rainfall has been summarized in a linear regression equation:y=a+b 1 x 1+b 2 x 2, withy=mean number of weather-working hours per day per half-monthly period, x1=mean daily rainfall per half-monthly period, x2=number of dry days per half-monthly period.For chosen percentiles of the frequency distribution ofy the corresponding number of weather-working hours in the same period can be estimated for future years. Taking the (two dimensional) frequency distribution of x1 and x2 as fixed, confidence intervals for the estimated number of weather-working hours can be calculated.
Zusammenfassung Es wird eine Methode zur Abschätzung der Stundenzahl, während der ein Mähdrescher innerhalb einer bestimmten Ernteperiode eingesetzt werden kann, besprochen. Die Methode beruht auf einer Untersuchung über die Beziehung zwischen der täglichen Regenmenge und der Möglichkeit des Mähdrescher-Einsatzes, welche von 60 Beobachtern Stunde für Stunde geschätzt wurde (Arbeitswetter-Stunden).Die Beziehung zwischen der Möglichkeit des Mähdrescher-Einsatzes und der Regenmenge wurde für die Jahre 1964, 1965 und 1966 in einer linearen Regresionsgleichung dargestellt:y=a+b 1x1+b 2x2, woy=mittlere Zahl von Arbeitswetter-Stunden pro Tag je Monatshälfte, x1=mittlere tägliche Regenmenge pro Monatshälfte, x2=Zahl der Trockentage pro Monatshälfte.Man kann für ausgewählte Perzentile der Häufigkeitsverteilung vony die entsprechende Zahl der Arbeitswetter-Stunden in derselben Periode für künftige Jahre abschätzen.Aus der zweidimensionalen Häufigkeitsverteilung von x1 und x2 können Konfidenzbereiche für die geschätzte Zahl der Arbeitswetter-Stunden berechnet werden.
Résumé On discute une méthode permettant d'estimer le nombre d'heures durant lesquelles une moissonneuse-batteuse peut être engagée au cours d'une période déterminée de moisson. Cette méthode repose sur une recherche des relations existantes entre la somme journalière de précipitation et les possibilités d'utilisation de la machine, relevées d'heure en heure par 60 observateurs (heures employables de machine).La relation entre la quantité de précipitations et la possibilité d'emploi d'une moissonneuse-batteuse est représentée par des équations linéaires de régression pour 1964 aussi bien que pour 1965 et 1966:y=a+b 1x1+b 2x2. La signification des symboles est la suivante:y=le nombre moyen d'heures employables de machine par jour, calculé par un demi-mois,x 1=la quantité journalière moyenne de précipitaations par un demi-mois, x1=la quantité journalière moyenne de précipitaations par un demi-mois, x2=le nombre de jours secs par un demi-mois.Partant de percentiles choisis de la distribution de fréquences dey, il est possible d'éstimer le nombre d'heures employables des moissonneuse-batteuses dans la même période pour les années a venir.Disposant de la distribution de fréquences des deux variablesx 1 etx 2 on peut calculer des intervalles de confidence pour le nombre estimé d'heures employables de machine par jour.

With 1 Figure  相似文献   

2.
A Random Displacement Model (RDM) and a Langevin Equation Model (LEM) are used to simulate point releases in a complex flow around a building. The flow field is generated by a three-dimensional finite element model that uses the standardk- model to parameterize the turbulence. The RDM- and LEM-calculated concentration fields are compared, with particular emphasis on the structure in regions with high turbulence and/or recirculation. RDM and LEM results are similar qualitatively, but RDM tends to predict lower concentration levels. In part this is due to the higher early-time diffusion. However, the expected convergence at later times is prevented by the interaction of the diffusion with the strongly inhomogeneous mean flow.Notation a i coefficient in the Langevin equation - b ij coefficient in the Langevin equation - C 0 the universal constant associated with the Lagrangian structure function - H building height (22.5 m) - K eddy viscosity - K k eddy viscosity used in the definition of the off-diagonal Reynolds stresses - k turbulent kinetic energy - LEM Langevin Equation Model - p 1 local unit vector in thexy-plane, orthogonal tos - p 2 local unit vector, orthogonal to boths andp 1 - RDM Random Displacement Model - s local unit vector in the streamline direction - T local decorrelation time (Lagrangian time scale) - U magnitude of the local Eulerian mean wind velocity - u s total velocity in the streamline direction - u 1 velocity component in thexy-plane, orthogonal to the streamline direction - u 2 velocity component orthogonal to bothu s andu 1 - i mean Eulerian wind velocity - W i stochastic vector-valued Wiener process - x unit vector inx-direction - y unit vector iny-direction - z unit vector inz-direction - angle between thexy-plane and the mean wind streamline - angle between the projection in thexy-plane of the streamline and thex-axis - ij the Kronecker delta function - rate of turbulence dissipation - i/ga the part ofa i that contains mean wind and turbulence gradients - ij inverse of a Reynolds stress tensor component - ij shorthand for a quantity that defines a part of i/ga - i shorthand for a quantity that defines a part of i/ga - ij Reynolds stress tensor component  相似文献   

3.
Measured spectra ofθ x,θ y,θ z, the derivatives of temperature in streamwise, lateral and vertical directions, respectively, indicate that the spectral densities ofθ z andθ y are nearly similar but significantly different from the spectral density ofθ x. The high-frequency parts of the three spectra satisfy, in a qualitative sense, local isotropy requirements. In the high-frequency end of the inertial subrange, the relative behaviour of spectra ofθ x,θ y andθ z is also consistent with local isotropy.  相似文献   

4.
The profound impact of solar irradiance variations on the decadal variability of Earth' s climate has been investigated by previous studies.However,it remains a challenge to quantify the energetic particle precipitation(EPP) influence on the surface climate,which is an emerging research topic.The solar wind is a source of magnetospheric EPP,and the total energy input from the solar wind into Earth' s magnetosphere(E_(in)) shows remarkable interdecadal and interannual variability.B ased on the new E_(in) index,this study reveals a significant interannual relationship between the annual mean E_(in)and Eurasian cold extremes in the subsequent winter.Less frequent cold events are observed over Eurasia(primarily north of 50°N) following the higher-than-normal E_(in) activity in the previous year,accompanied by more frequent cold events over northern Africa,and vice versa.This response pattern shows great resemblance to the first empirical orthogonal function of the variability of cold extremes over Eurasia,with a spatial correlation coefficient of 0.79.The pronounced intensification of the positive North Atlantic Oscillation events and poleward shift of the North Atlantic storm track associated with the anomalously higher E_(in) favor the anomalous extreme atmospheric circulation events,and thus less frequent extreme cold temperatures over northern Eurasia on the interannual time scale.It is further hypothesized that the wave-mean flow interaction in the stratosphere and troposphere is favorable for the connection of E_(in) signals to tropospheric circulation and climate in the following winter.  相似文献   

5.
2003年淮河流域大水期间体积降水量的研究   总被引：5，自引：2，他引：5  
姚学祥  徐晶 《气象学报》2004,62(6):803-813
针对 2 0 0 3年梅雨期淮河流域大水提出了体积降水量的概念及其计算方法 ,在计算出淮河流域和其各子流域逐日和总体积降水量的基础上 ,将体积降水量与水文站的水位和流量进行了对比分析。结果表明 :水位对累计体积降水量有较好的即时响应 ,流量对体积降水量有较好的延迟响应。另外 ,讨论了流域体积降水量的预报问题 ,用国内外数值天气预报产品和中央气象台指导预报产品 ,进行了流域体积降水量预报试验 ,并对预报结果进行了检验分析。结果表明 :在目前天气预报水平条件下 ,利用数值天气预报和中央气象台业务预报产品制作体积降水量是可行的 ,能够延长洪水预报的预见期 ;而且 ,数值天气预报产品在预报体积降水量方面有明显的优势 ,因此可以直接利用数值天气预报产品进行体积降水量的客观预报 ,为防汛工作提供重要的依据。  相似文献   

6.
Summary High spatial resolution data from an airborne microwave imaging radiometer operating at 92 and 183 GHz (0.32 and 0.16 cm wavelengths) are compared with ground-based radar data for a series of observations of precipitating convective systems. An inverse relationship between microwave brightness temperature (T B ) and radar-derived rain rate (RR) is observed. Differences in the empirical curves between midlatitude and tropical cloud systems are related to the differing microphysical and dynamical environments.ColdT B features in the aircraft images are collocated with high reflectivity values in the radar data. Over a water back-ground, which has a low surface emissivity at these frequencies, small convection produces an increase inT B at 92 GHz due to emission by liquid water in the cloud. As the convection deepens and ice forms,T B at both frequencies decreases rapidly with increasing rain rate. The large decrease inT B with increasing storm intensity is due to scattering of upwelling radiation by precipitation-sized ice particles within the clouds. With high rain rates, there is little difference betweenT B observed over both land and water backgrounds.TheT B features in the aircraft imagery are qualitatively similar to radar echoes in plan position indicator (PPI) images. Areas of extremely coldT B (<150 K) coincide with high radar reflectivities. The highest correlations between microwave and radar features with regard to location, intensity, and shape occur more frequently with mid-to upperlevel echoes rather than low-level reflectivity features.With 12 Figures  相似文献   

7.
Summary The empirical rainfall distributions of 42 monthly time series in Spain, for both raw data and for residual series, after removing the seasonal component, were fitted with six theoretical distribution functions (d f's). The distributions were fitted with 2, 3, and 4 parameters, which had been used previously with meteorological variables. The parameters of the probability density functions were calculated using maximum likelihood estimation procedures, and six statistics were examined to identify the bestd f to fit each series.The observations {X t},t = 1,,N were assumed to consist of a seasonal componentS t described by an harmonic process model, whose frequencies, number of terms, amplitudes and phases are unknown constants, plus a residualY t which is a general linear process (for example, an autoregressive, moving-average, or mixed autoregressive/movingaverage process).The frequencies and number of terms in the harmonic process were chosen via a periodicity test, the Siegel test (1980). This is essentially a uniparametric family of periodicity tests which contains the Fisher test as a special case, which improves the results of the latter in cases of simultaneous periodicity at several frequencies. The remaining unknown parameters were determined by regression analysis.It is well known that precipitation has a positively skewed, non-Gaussian distribution. However, the results obtained here show that while the statistical techniques used to eliminate the seasonal component do not require the original data normal distribution, when they are normally distributed the quality of the estimates is better.With 7 Figures  相似文献   

8.
Measurements of NOx,y were made at Alert, Nunavut, Canada (82.5° N, 62.3° W) during surface layer ozone depletion events. In spring 1998, depletion events were rare and occurred under variable actinic flux, ice fog, and snowfall conditions. NOy changed by less than 10% between normal, partially depleted, and nearly completely depleted ozone air masses. The observation of a diurnal variation in NOx under continuous sunlight supports a source from the snowpack but with rapid conversion to nitrogen reservoirs that are primarily deposited to the surface or airborne ice crystals. It was unclear whether NOx was reduced or enhanced in different stages of the ozone depletion chemistry because of variations in solar and ambient conditions. Because ozone was depleted from 15–20 ppbv to less than 1 ppbv in just over a day in one event it is apparent that the surface source of NOx did not grossly inhibit the removal of ozone. In another case ozone was shown to be destroyed to less than the 0.5 ppbv detection limit of the instrument. However, simple model calculations show that the rate of depletion of ozone and its final steady-state abundance depend sensitively on the strength of the surface source of NOx due to competition from ozone production involving NOx and peroxy radicals. The behavior of the NO/NO2 ratio was qualitatively consistent with enhanced BrO during the period of active ozone destruction. The model is also used to emphasize that the diurnal partitioning of BrOx during ozone depletion events is sensitive to even sub ppbv variations in O3.  相似文献   

9.
The Bowen ratio (B) is impacted by 5 environmental elements: soil moisture availability, m, the ratio of resist-ances between atmosphere and soil pores, ra/rd, atmospheric relative humidity, h, atmospheric stability, ΔT, and environment temperature. These impacts have been investigated over diverse surfaces, including bare soil, free water surface, and vegetation covered land, using an analytical approach. It was concluded that: (a) B is not a continuous function. The singularity exists at the condition αhcb=h, occurring preferably in the following conditions: weak turbulence, stable stratified stability, dry soil, and humid air, where hcb, defined by Eq.(11) is a critical variable. The existence of a singularity makes the dependence of B on the five variables very complicated. The value of B approaches being inversely proportional to m under the conditions m≥mfc (the soil capacity) and / or ra/rd→0. The proportional coefficient changes with season and latitude with relatively high values in winter and over the poles; (b) B is nearly independent of ra/rd during the day. The impact of m on B is much larger as compared to that of ra/rd on B, (c) when h increases, the absolute value of B also increases; (d) over bare soil, when the absolute surface net radiation increases, the absolute value of B will increase. The impact of RN on B is larger at night than during the day, and (e) over plant canopy, the singularity and the dependcies of B on m, ra , and h are modified as compared to that over bare soil. Also (i) during the daytime unstable condition, m exerts an even stronger impact on B, at night, however, B changes are weak in response to the change in m; (ii) the value of B is much more sensitive in response to the changes of turbulent intensity; (iii) the B response to the variation of h over a vegetation covered area is weaker; and (iv) the singularity exists at the condition hcp=h instead of αhcb=h as over bare soil, where hcp is defined by Eq.(49). The formulas derived over bare soil also hold the same when applied to free water bodies as long as they are visualized as a special soil in which the volumetric fraction of soil pore is equal to one and are fully filled with water. Finally, the above discussions, are used to briefly study the impact on the thermally induced mesoscale circulations.  相似文献   

10.
Summary The broadband solar absorptivity concept is employed to parameterize the aerosol absorption effect. The solar radiation model developed by Liou and his associates was modified to incorporate the parameterization of solar radiative transfer in an aerosol layer. Comparison of the results from this method with other schemes exhibits close agreement. A Sahara dust storm case was also chosen to test the performance of the present model, and the computed heating rate profiles agree well with calculations based on optical properties derived from observations for both clear and dust cases. In general, enhanced heating due to aerosol absorption of solar flux occurs particularly in the lower troposphere (below 5 km). The heating rate is independent of the scattering partition factor (), but the planetary albedo increases with . Further study shows that the aerosol heating is sensitive to the surface albedo (r s ) and to the cosine of the solar zenith angle (µ 0). The decrease inr s and/or increase inµ 0 lower the solar heating rate, the planetary albedo and the atmospheric absorptivity, but raise the surface absorptivity due to reduced multiple reflection between the atmosphere and surface.With 9 Figures  相似文献   

11.
传统的空气质量模型多使用简化的光化学反应机制来模拟大气污染物的形成.这些机制主要基于烟雾箱实验拟合的反应速率和产物来模拟二次产物（如臭氧（O3））前体物的氧化反应,具有一定的不确定性,导致模拟结果产生偏差.针对该问题,本研究将详细的大气化学机理（MCMv3.3.1）与美国国家环境保护局研制的第三代空气质量预报和评估系统CMAQ相结合（CMAQ-MCM）,模拟研究长三角地区2015年8月27—9月5日臭氧高发时段的空气质量.CMAQ-MCM模型可以较好地模拟长三角地区6个代表城市O3和其前体物随时间的变化趋势.对模拟的O3日最大8 h平均浓度的统计分析表明,徐州表现最好（标准平均误差=-0.15,标准平均偏差=0.23）.在长三角地区,居民源对挥发性有机物（VOCs）的贡献最大,占39.08%,其次是交通运输（33.25%）和工业（25.56%）.能源对总VOCs的贡献最小,约为2.11%.对活性氧化氮（NOy）的分析表明,其主要组分是NOx（80%）,其次是硝酸（HNO3）（<10%）.O3的空间分布与NOy和NOx非常相似.HCHO等其他氧化产物的分布与NOx相似,这很可能是由于在高NOx条件下VOCs氧化产生的产物.甲基乙烯基酮（MVK）和甲基丙烯醛（MACR）的空间分布与自然源VOCs （BVOCs）非常相似,表明长三角地区MVK和MACR主要由BVOCs氧化生成.长三角地区受到人为源和自然源排放相互作用的影响.  相似文献   

12.
In situ measurements of [OH], [HO2] (square brackets denote species concentrations), and other chemical species were made in the tropical upper troposphere (TUT). [OH] showed a robust correlation with solar zenith angle. Beyond this dependence, however, [OH] did not correlate to its primary source, the product of [O3] and [H2O] ([O3]?[H2O]), or its sink [NOy]. This suggests that [OH] is heavily buffered in the TUT. One important exception to this result is found in regions with very low [O3], [NO], and [NOy]. Under these conditions, [OH] is highly suppressed, pointing to the critical role of NO in sustaining OH in the TUT and the possibility of low [OH] over the western Pacific warm pool due to strong marine convections bringing NO-poor air to the TUT. In contrast to [OH], [HOx] ([OH] + [HO2]) correlated reasonably well with [O3]?[H2O]/[NOy], suggesting that [O3]?[H2O] and [NOy] are the significant source and sink, respectively, of [HOx].  相似文献   

13.
Simultaneousindependent measurements of NOy and NOx(NOx= NO + NO2) by high-sensitivitychemiluminescence systems and of PAN (peroxyacetylnitrate) and PPN (peroxypropionyl nitrate) by GC-ECDwere made at Spitsbergen in the Norwegian Arcticduring the first half year of 1994. The average mixingratio of the sum of PAN and PPN (denoted PANs)increased from around 150 pptv in early winter to amaximum of around 500 pptv in late March, whereasepisodic peak values reached 800 pptv. This occurredsimultaneously with a maximum in ozone which increasedto 45–50 ppbv in March–April. The average NOxmixing ratio was 27 pptv and did not show any cyclethrough the period. The NOy mixing ratio showeda maximum in late March, while the difference betweenNOy and PAN decreased during spring. This is anindication of the dominance of PAN in the NOybudget in the Arctic, but possible changes in theefficiency of the NOy converter could alsocontribute to this. Although most PAN in theArctic is believed to be due to long range transport,the observations indicate local loss and formationrates of up to 1–2 pptv h-1 in April–May.Measurements of carbonyl compounds suggest thatacetaldehyde was the dominant, local precursor ofPAN.Now at 1.  相似文献   

14.
The response of tropospheric ozone to a change in solar UV penetration due to perturbation on column ozone depends critically on the tropospheric NO x (NO+NO2) concentration. At high NO x or a polluted area where there is net ozone production, a decrease in column ozone will increase the solar UV penetration to the troposphere and thus increase the tropospheric ozone concentration. However, the opposite will occur, for example, at a remote oceanic area where NO x is so low that there is net ozone destruction. This finding may have important implication on the interpretation of the long term trend of tropospheric ozone. A change in column ozone will also induce change in tropospheric OH, HO2, and H2O2 concentrations which are major oxidants in the troposphere. Thus, the oxidation capacity and, in turn, the abundances of many reduced gases will be perturbed. Our model calculations show that the change in OH, HO2, and H2O2 concentrations are essentially independent of the NO x concentration.  相似文献   

15.
Summary Hourly screen temperatures were collected over a four-year period for six stations from the Inn valley floor (580 masl) up the Nordketten slope toHafelekar (2260 masl). In this paper, we develope methods for correcting the observed screen temperatures, converting them into temperatures of the free valley atmosphere. Because of the combined effects of the screen and the slope layer, slope temperatures are, on average, too cold at night and too warm in the daytime.A correction function modelled after the daily march of solar radiation works well for all stations except theHungerburg. Temperatures there are, on average, up to 2.5°C too cold on clear nights, compared to the valley atmosphere, and too warm by up to 1.8°C in the daytime. A modified correction function was derived for the Hungerburg site.The suitability of the correction functions is checked by various, mostly indirect methods, the most important of which utilizes statistics of the daily range of temperature. As a final, integral check on our correction scheme, we compute vertical averages of these daily ranges, obtaining excellent agreement with mean daily ranges derived barometrically from hourly pressure recordings atInnsbruck andHafelekar.With 7 Figures  相似文献   

16.
An analysis of the periodicities found in the Nimbus-7 satellite measurements of solar irradiance (Solar Constant) indicates variations on three scales. Two of these variations are shown to be related to variations in solar activity as given by various indicators of solar photosphere disturbances. The high frequency periodicity is due to the solar rotation period. The second periodicity is based on the integral effect of the high frequency oscillation over an 11 year solar cycle. The third variation (secular trend) is discussed in regard to the high precision cavity data and the recent record of high altitude solar constant measurements.  相似文献   

17.
Measurements of NOx (NO +NO2) and the sum of reactive nitrogenconstituents, NOy, were made near the surface atAlert (82.5°N), Canada during March and April1998. In early March when solar insolation was absentor very low, NOx mixing ratios were frequentlynear zero. After polar sunrise when the sun was abovethe horizon for much or all of the day a diurnalvariation in NOx and NOy was observed withamplitudes as large as 30–40 pptv. The source ofactive nitrogen is attributed to release from the snowsurface by a process that is apparently sensitized bysunlight. If the source from the snowpack is a largescale feature of the Arctic then the diurnal trendsalso require a competing process for removal to thesurface. From the diurnal change in the NO/NO2ratio, mid-April mixing ratios for the sum of peroxyand halogen oxide radicals of 10 pptv werederived for periods when ozone mixing ratios were inthe normal range of 30–50 ppbv. Mid-day ozoneproduction and loss rates with the active nitrogensource were estimated to be 1–2 ppbv/day and in nearbalance. NOy mixing ratios which averaged only295±66 pptv do not support a large accumulation inthe high Arctic surface layer in the winter and springof 1998. The small abundance of NOy relative tothe elevated mixing ratios of other long-livedanthropogenic constituents requires that reactivenitrogen be removed to the surface during transport toor during residence within the high Arctic.  相似文献   

18.
Summary  This paper is a contribution to experimental meteorology: A sea-breeze front was investigated by aircraft observations and thorough numerical analysis using an unprecedented number of runs crossing the same front within a timespan of . The 33 runs were flown in a situation of offshore geostrophic wind of 5 m/s in 1000 hPa and with the strategy of obtaining information on the four-dimensional field (t=time, x=cross-coastal coordinate, y=coast-parallel coordinate, z=height): 9 runs in x-direction (and reverse) at different heights to yield x,z-cross-sections of the observed meteorological quantities (specific humidity q, potential temperature Θ and the components u, v and w of the wind velocity), assuming a frozen structure in time; the next 7 runs again in x-direction but all at the same level and on the same track to yield x,t-diagrams of the same quantities in order to study the temporal changes compared to those with x and z; the next 10 runs as a zig-zagging flight track crossing the front but drifting in y-direction, all at the same height, in order to obtain the y-dependency; andfinally 7 runs for another x,z-cross-sectional analysis, which can be compared to that evaluated from the runs at the beginning of the mission. The paper describes the 4-dimensional dependencies in detail. Pure x-variations at constant z are expressed by VCM low-pass filtered space series (VCM=variance conserving multiresolution, according to Howell and Mahrt, 1994). The x,z-analyses are similar to those in Kraus et al. (1990) and Finkele et al. (1995) verifying these results. The comparison of the x,z-studies gained from the data at the beginning and at the end of the mission show how the sea-breeze frontal area changes its structure. The fluctuations (in time) revealed by the low-pass filtered x,t-runs (same track and same height) are smaller than the contour intervals chosen in the x,z-cross-sections. This shows, that the single runs, from which the x,z-cross-sections are constructed, reliably and significantly contribute to the interpolated structure. The paper also demonstrates the overall development of the front within the 31/2 h of continuous observation. The x,y-fields demonstrate that the y-dependency of the various quantities is generally one order of magnitude smaller than the x-dependency and that the assumption of negligible y-dependency holds in the first order of approximation for a fairly homogeneous coast. Convective disturbances of a horizontal scale of 1 to 4 km at the landward side of the front, embedded in the offshore flow and bouncing against the landward propagating sea-breeze front, considerably contribute to variations of the frontal propagation speed and of the frontal shape and also to changes of the parameters with the along-frontal coordinate y. Received April 24, 1998 Revised November 3, 1998  相似文献   

19.
粤东复杂地形上空的大气湍流强度及扩散参数   总被引：3，自引：0，他引：3  
在具有复杂下垫面的粤东梅州市采用追踪平衡球的双经纬仪观测和美制ＧＩＬＬ三轴风速仪观测，分别测定了该地区拉格朗日系统和欧拉系统的湍流脉动量。然后用不同参照系的泰勒公式，分别计算出大气的水平和垂直的湍流强度及扩散参数，并与ＰＧ法之计算值和ＢＮＬ实验结果比较，发现距地面１００ｍ以上高空在各类稳定度层结条件下大气扩散参数均比ＰＧ值和ＢＮＬ值偏大。  相似文献   

20.
Zusammenfassung Der mechanische Teil eines Seismographen, bestehend aus einem Pendel und eventuell einem vergrößernden Hebelsystem, wird alsmechanischer Empfänger des Seismographen bezeichnet; es ist vorausgesetzt, daß er einen Freiheitsgrad besitzt.u ist der Indikator des mechanischen Empfängers. Die Bewegungen des Gestelles, in dem das Seismographenpendel montiert ist (d. h. des KoordinatensystemsO y ), sind gegeben durch den Vektor , der die Translationen des Gestelles beschreibt, und den Tensor , durch den die Rotationen bestimmt sind. Mit Hilfe der Gl. (17) bis (21) kann die Indikatorgleichung auch unter Berücksichtigung nicht-linearer Glieder aufgestellt werden. Die Gl. (25) ist die lineare Form der Indikatorgleichung. Die StörungsfunktionG(t) auf der rechten Seite der Gl. (25) kann in die einfache Form (32) gebracht werden, wenn man für das GestellO y beliebige, im allgemeinen nicht kleine, Bewegungen annimmt. Die Vektorenm undB und der symmetrische TensorC sind Instrumentalkonstanten, welcheÜbertragungsfaktoren genannt werden. Die Vektorenm undB und der symmetrische TensorS hängen von der Bewegung vonO y ab. Es wird gezeigt, in welcher Weise diese Faktoren von der Lage des KoordinatensystemsO y in bezug auf das Gestell abhängen. Mit Hilfe der Übertragungsfaktoren wird eine Klassifikation aller nur denkbaren mechanischen Empfänger mit einem Freiheitsgrad durchgeführt. Es wird ein Additionstheorem für solche Empfänger aufgestellt; es erlaubt die Zusammenstellung von einfachen Modellen für die verschiedenen Typen von mechanischen Empfängern.
Summary The mechanical part of a seismograph, consisting of a pendulum often supplied by a mechanical system of magnification, is called themechanical receiver of the seismograph. The receiver is assumed to have one degree of freedom.u is the indicator of the receiver. The motions of the case containing the receiver (systemO y ) are given by the vector describing the translations and the tensor describing the rotations. By means of the equations (17) to (21), the indicator equation can be established, non-linear terms being included. (25) is the linear form of the indicator equation. The motion ofO y being assumed arbitrary and generally not small, the right hand termG(t) of (25) can be put in the simple form (32). The vectorsU andB and the symmetrical tensorC are instrumental constants, calledresponse factors, the vectorsm andB and the symmetrical tensorS depend on the motion ofO y . It is shown, in which way the response factors depend on the system of coordinatesO y chosen. By aid of these factors all possible types of mechanical receivers of one degree of freedom have been classified. An addition theorem for mechanical receivers has been established and applied to the construction of simple models of such receivers.
Résumé La partie mécanique d'un sismographe est un pendule, éventuellement muni de leviers amplificateurs. Cette partie est nomméerécepteur mécanique du sismographe. On suppose qu'elle possède un degré de liberté. Les déplacementsu de l'indicateur relatifs au support sont supposés petits. Au contraire les mouvements du supportO y sont arbitraires; ils sont donnés par le vecteur (translations) et le tenseur (rotations). A l'aide des équations (17) à (21) on peut établir l'équation de l'indicateur, membres non linéaires inclus. L'équation linéaire (25) est la forme la plus simple de l'équation de l'indicateur. Le second membreG(t) de l'équation (25), nommé «fonction d'excitation», peut être mis à la forme simple (32). Les vecteursm etB et le tenseur symétriqueC, nommés «facteurs de transmission» sont des grandeurs caractéristiques du récepteur. Les vecteursm etB et le tenseur symétriqueS dépendent du mouvement deO y . On démontre la connexion entre ces facteurs et la position du systèmeO y de coordonnées par rapport au support auquel il est fixé. A l'aide des facteurs de transmission toutes les formes possibles de récepteurs mécaniques d'un degré de liberté ont été classifiées. Un théorème d'addition pour les récepteurs mécaniques a été établi. A l'aide de ce théorème, des modèles simples des différents types de récepteurs ont été construits.

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